U.S. patent number 4,956,033 [Application Number 07/355,278] was granted by the patent office on 1990-09-11 for process for reclaiming plastic containers.
This patent grant is currently assigned to Norman R. Martin. Invention is credited to Norman R. Martin, Barclay J. McMullen.
United States Patent |
4,956,033 |
Martin , et al. |
September 11, 1990 |
**Please see images for:
( Certificate of Correction ) ** |
Process for reclaiming plastic containers
Abstract
A process for reclaiming plastic containers includes the steps
of providing containers having an adhesive composition affixed
thereto, sorting the containers, and internally pressurizing the
containers. The steps also include adding heated liquid into the
containers for liquefying residue within the containers and for
loosening an adhesive composition affixed to the containers. The
steps further include allowing the containers to depressurize,
removing the liquid from the containers, and granulating the
containers thereby forming granular masses.
Inventors: |
Martin; Norman R. (Rochester
Hills, MI), McMullen; Barclay J. (Bloomfield Hills, MI) |
Assignee: |
Martin; Norman R. (Rochester
Hills, MI)
|
Family
ID: |
23396892 |
Appl.
No.: |
07/355,278 |
Filed: |
May 22, 1989 |
Current U.S.
Class: |
156/94;
134/104.4; 264/918; 15/59; 156/154; 156/250; 156/510; 156/921;
156/709 |
Current CPC
Class: |
B08B
9/083 (20130101); B29B 17/02 (20130101); Y10T
156/1052 (20150115); B29K 2711/12 (20130101); Y02W
30/62 (20150501); B29K 2023/06 (20130101); Y10T
156/1142 (20150115); Y10S 156/921 (20130101); Y10T
156/12 (20150115); B29K 2067/00 (20130101); Y02W
30/622 (20150501); Y10S 264/918 (20130101) |
Current International
Class: |
B08B
9/08 (20060101); B29B 17/02 (20060101); B32B
035/00 (); B32B 031/18 () |
Field of
Search: |
;15/59,60 ;134/104.4
;156/154,344,250,510,584,94 ;264/37 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Dawson; Robert A.
Attorney, Agent or Firm: Harness, Dickey & Pierce
Claims
What is claimed is:
1. A process for reclaiming plastic containers, comprising the
steps of:
(a) Providing used containers or containers which do not pass
quality control standards at manufacture having an adhesive
composition affixed thereto;
(b) Sorting said containers according to volume;
(c) Removing a tamper resistant ring from said container, if
required;
(d) Uncapping said container, if required;
(e) Internally pressurizing said container from about 18 pounds per
square inch to about 40 pounds per square inch;
(f) Adding at least one ounce of heated liquid into said container
for liquefying residue within said container and for loosening an
adhesive composition affixed to said container;
(g) Allowing said container to depressurize;
(h) Removing a base from said container, if required;
(i) Removing a label from said container, if required, by external
spraying;
(j) Removing said liquid from said container;
(k) Granulating said container thereby forming granular masses;
and
(l) Removing excess liquid from said granular masses.
2. The process of claim 1 wherein said heated liquid is water
having a temperature from about 125.degree. F. to about 190.degree.
F.
3. The process of claim 2 wherein said water has a temperature from
about 180.degree. F. to about 190.degree. F.
4. The process of claim 1 wherein steps 1(c) and 1(d) are performed
simultaneously.
5. The process of claim 1 wherein step 1(d) is performed prior to
step 1(c).
6. The process of claim 1 further including granulation of said
base for reclaiming.
7. The process of claim 1 further including adding from about one
ounce of heated liquid to about the entire internal volume of said
container with heated liquid.
8. The process of claim 7 wherein said internal volume is
pre-selected.
9. The process of claim 1 wherein said internally pressurizing of
said container is from about 18 pounds per square inch to about 40
pounds per square inch of said container.
10. The process of claim 1 wherein said external spraying of said
container is from about 300 pounds per square inch to about 1500
pounds per square inch.
11. The process of claim 10 wherein said external spraying is from
about 750 pounds per square inch to about 850 pounds per square
inch.
12. The process of claim 1 wherein said heated liquid is removed
from said container by slicing said container diametrically through
about 80 to about 95% of its diameter.
13. The process of claim 12 wherein said slicing occurs about one
inch from a bottom of said container.
14. A process for reclaiming plastic containers, comprising the
steps of:
(a) providing container having an adhesive composition affixed
thereto;
(b) sorting said containers;
(c) removing a tamper resistant ring from said container, if
required;
(d) uncapping said container, if required;
(e) internally pressurizing said container;
(f) adding heated liquid into said container for liquefying residue
within said container and for loosening an adhesive composition
affixed to said container;
(g) allowing said container to depressurize;
(h) removing a base from said container, if required;
(i) removing a label from said container, if required, by external
spraying;
(j) removing said liquid from said container; and
(k) granulating said container thereby forming granular masses.
15. A process for reclaiming plastic containers, comprising the
steps of:
(a) providing containers having an adhesive composition affixed
thereto;
(b) sorting said containers;
(c) internally pressurizing said container;
(d) adding heated liquid into said container for liquefying residue
within said container and for loosening an adhesive composition
affixed to said container;
(e) allowing said container to depressurize;
(f) removing said liquid from said container; and
(g) granulating said container thereby forming granular masses.
Description
BACKGROUND OF THE INVENTION
1. Technical Field
The present invention is directed toward a process for reclaiming
plastic containers. More particularly, the invention is useful when
reclaiming plastic such as what is commonly known in the industry
as one half liter, one liter, two liter and three liter
polyethylene terephthalate containers or containers of similar
composition. These types of containers are used in the beverage
industry and are what are generally known as "disposable"
containers. Various techniques have been developed for reclaiming
and/or recycling plastic beverage containers. However, these
various techniques have certain drawbacks which are not associated
with the present invention.
U.S. Pat. No. 4,033,804 (Baldyga) discloses a process of reclaiming
thermoplastic articles. Baldyga teaches that the bottle is
delabeled by relieving orientation stresses beneath the label
sufficiently to cause enough shrinkage for the bottle and the label
to separate.
U.S. Pat. No. 3,317,642 (Bailey) teaches and describes a method for
stabilizing the volume of a plastic container, such as a plastic
milk bottle. In other words, Bailey discloses a method of producing
plastic containers with calibrated volumes.
U.S. Pat. No. 3,662,453 (Meal, et al) discloses an apparatus and a
process for stripping a heat shrinkable material extending
peripherally about a rigid article such as an electrical
connector.
U.S. Pat. No. 3,870,181 (Sincock) teaches the manufacture of a
beverage bottle formed under pressure wherein the bottle consists
primarily of polymerized acrylonitrile monomer.
U.S. Pat. No. 4,067,826 (Emery) teaches a method for recovering
mixed plastic materials from the group consisting of at least
polyvinyl chloride and polyethylene.
U.S. Pat. No. 4,599,131 (Matuszak) discloses a high speed rolling
apparatus for delabeling plastic containers. Matuszak teaches that
a series of rollers flatten the plastic bottle, that some of the
rollers provide heat to the flattened bottle for loosening the
bottle label, and that brush rollers eventually remove the label
from the bottle.
Unfortunately, these prior approaches have their own set of
drawbacks. For example, Baldyga (U.S. Pat. No. 4,033,804) requires
shrinkage of the bottle before the label can be removed. Matuszak
(U.S. Pat. No. 4,599,131) requires heat; that the bottle be
flattened and thereafter scrubbed by brush rollers before the label
can be removed.
The present invention does not require such a complicated series of
steps for its operation. Therefore, the present invention can be
economically and easily adapted for reclaiming containers.
2. SUMMARY OF THE INVENTION
A primary object of the present invention is to provide a process
for reclaiming plastic containers. The reclaimed plastic containers
can thereafter be recycled and used in the beverage or other
industries where polyethylene terephthalate or similar plastics are
used.
It is another object of the present invention to provide a process
for reclaiming plastic containers which is economical to operate
and use.
Pursuant to the present invention, the process includes the steps
of providing used beverage containers, sorting those containers
according to their volume, removing the tamper resistant ring,
uncapping the container if it has not already been uncapped,
expanding the container through pressure, injecting heated liquid
into the container, removing the label from the container,
granulating the delabeled container and removing any excess liquid
therefrom. The granulated container can then be recycled.
Another feature in accordance with the present invention can be the
removal of the base from the container. This is particularly so,
when the base and the container are composed of different plastic
compositions. Further, the base can also be recycled.
Within the scope of the present invention, the containers can be
sorted by volume either by hand or with an electromechanical sorter
available in the industry. Further, the bottles can, if desired, be
sorted by color either by hand or by any suitable device in the
art.
Additionally and in accordance with the present invention, the
liquid can be water or any other suitable liquid which will,
loosen, dissolve and/or remove remaining residue from the
container.
Further still and within the scope of the present invention, the
removal of the tamper resistant seal, the uncapping of the
containers can be done manually or with mechanical apparatus.
Moreover, whether a container is capped or uncapped can be detected
by a commercially available sensor.
DESCRIPTION OF THE INVENTION
Although the disclosure hereof is detailed to enable those skilled
in the art to practice the invention, the embodiment disclosed
herein merely exemplifies the present invention which can also be
embodied in other processes.
Viewing FIG. 1, container 10 can be what is known in the industry
as a one-half, one, two or three liter container. Container 10 is
generally composed of polyethylene terephthalate or other similar
plastic.
Container 10 is provided with base 12 for supporting container 10
in an upright position when container 10 is filled with a beverage
(not shown). Base 12 is generally composed of high density
polyethylene.
Container 10 is further provided with cap 14 and tamper resistant
ring 16 for insuring the integrity of the beverage under pressure
until the beverage is to be consumed. Cap 14 and tamper resistant
ring 16 can be secured to container 10 via any manner acceptable in
the art.
Further still, container 10 can be provided with container label 18
for identifying the beverage in container 10. Container label 18
can be composed of polyethylene terephthalate or other materials
such as paper or plastics other than polyethylene
terephthalate.
Base 12 and container label 18 are adhered to container 10 with
glue or other suitable composition for affixing base 12 and
container label 18 to container 10. More often than not, container
10 is also provided with pricing label 20. Pricing label 20 can be
composed of paper with an adhesive backing for affixing pricing
label 20 to container 10.
Turning to FIG. 2, a schematic of the present invention, the
various steps of the present invention are described. In step 1
used beverage containers 10 or containers which do not pass quality
control standards at manufacture are provided. In step 2 beverage
containers 10 are sorted by volume. Further, an additional step of
sorting the containers by color can be performed (not shown in FIG.
2) The sorting of the containers by either volume or color can be
done manually or electromechanically with the use of commercially
available sorters.
In Step 3, after the containers have been sorted, tamper resistant
ring 16 is removed from container 10 either manually or with an
electromechanical apparatus suitable for that purpose as container
10 is transported through the process in accordance with the
present invention.
Step 4 includes the uncapping of the beverage container, if it is
required. This uncapping can be performed either manually or with
commercially available electromechanical apparatus. More
particularly, Step 3 and Step 4 can be performed simultaneously or
in inverse order.
After Step 4, uncapped container 10 are transported to an
electromechanical apparatus wherein the apparatus can provide
internal pressure and heated liquid to the internal uncapped
container 10. The aforenoted commercially available
electromechanical apparatus is similar or identical to the
apparatuses used by the bottling industry in pressurizing the
container and filling the container with the beverage which will
ultimately be sold to the consuming public.
Step 5 includes the internal pressurization of container 10. From
about 18 pounds per square inch to about 40 pounds per square inch
of pressure are provided to container 10. This internal
pressurization of container 10 causes container 10 to expand
outwardly thereby expanding label 18. When label 18 is expanded in
this manner it is stretched away from container 10 and thereafter
is not as stringently adhered to container 10.
In Step 6 at least one ounce of heated liquid is supplied or
injected into the beverage container for first liquefying any
remaining residue within the container and second causing heat
transfer from the internal container to the adhesive composition
affixing identifying label 18 and base 12 to container 10. The
heated liquid can be water or any other suitable liquid which will
remove any remaining residue from container 10. It has been
determined that the heated liquid operates proficiently from about
125.degree. F. to about 190.degree. F. However, it has further been
determined that a more preferred liquid temperature for removing
residue and loosening the adhesive composition affixing identifying
label 18 and base 12 to container is from about 180.degree. F. to
about 190.degree. F.
Importantly, Step 5 and Step 6 can be performed simultaneously or
in reverse order. Further, container 10 can have the heated liquid
added and be pressurized at the same time.
Because of the thermal forces involved, when the heated liquid is
added to container 10, additional expansion is created in container
10, label 18 and base 12.
As previously specified, at least one ounce of heated liquid is
injected into container 10. This volume of heated liquid is
sufficient for loosening any adhesive which has been used to affix
base 12 or label 18 to container 10.
After the adhesive securing base 12 to container 10 has been
loosened, Step 7 includes removal of base 12 from container 10
either manually or electromechanically with any commercially
acceptable device within the industry. Additionally, it has
unexpectedly been determined that the use of an abrasive pad
contacting base 12 while container 10 is being transported toward
its next step in the process within the scope of the present
invention is sufficient for removing base 12 from container 10.
After base 12 is removed from container 10, base 12 is transported
for granulation and is ultimately packaged for shipment and
recycling.
It should be understood at this time, that when identifying label
18 and container 10 are manufactured of the same or similar
material, it is unnecessary to separate identifying label 18 from
container 10. Thus, after depressurization, both label 18 and
container 10 can continue through the process in accordance with
the present invention for ultimate recycling without the
requirement of removing label 18 from container 10.
However, more often than not, the labels affixed and/or attached to
the beverage containers are not manufactured of the same
composition as the container, i.e. polyethelene terephthalate or a
composition compatible therewith. It then is necessary to continue
the steps within the scope of the present invention. For example,
many times a retailer will affix a paper-type adhesive retail
pricing label to the container on or above the container label.
When such an event occurs, step 6 in accordance with the present
invention can supply heated liquid for filling the container to a
pre-selected level for loosening the aforenoted retail pricing
label. After the retail pricing label has been loosened, it is
easily removed. Step 6 can provide from about one ounce of heated
liquid to about the entire internal volume of the container of
heated liquid for loosening adhesive.
Step 8 includes transporting container 10 through a series of high
pressure sprayers During step 6, container 10 is allowed to
depressurize (i.e., return to atmospheric pressure. Additionally,
during step 6,7 and 8 container 10 is allowed to cool which causes
label 18 to be further separated from container 10. It has been
determined within the scope of the present invention that
container's 10 volume during cooling returns to within plus or
minus 10% of its original volume. As previously indicated, the high
pressure sprayer removes any remaining labels from container 10. It
has been determined that the high pressure sprayers operate
proficiently when applying from about 300 pounds per square inch to
about 1500 pounds per square inch of sprayer pressure to container
10. A more preferable range of sprayer pressure to be applied to
container 10 is from about 750 pounds per square inch to about 850
pounds per square inch.
After container 10 has been subjected to high pressure spraying, it
is subjected to Step 9 wherein container 10 is sliced diametrically
through about 80 to 95% of its diameter. At this juncture, the
heated liquid is released from container 10. This heated liquid can
be recycled if desired. Further, it has been determined that Step 9
is more proficiently performed by slicing container 10 at
approximately one inch from the bottom of container 10.
Container 10 is transported for granulation and Step 10 includes
granulation of container 10 wherein granular masses are formed.
Granulation is accomplished by any device commercially acceptable
within the art.
Step 9 is not a prerequisite for Step 10, if the heated liquid is
removed from container 10 before granulation in another manner. For
example, container 10 can be drained either manually or
electromechanically by turning container 10 upside down and
allowing the heated liquid to drain. However, it has been
determined with the use of Step 9 the entire process within the
scope of the present invention can be practiced more
efficiently.
Step 10 granular masses are dried in accordance with Step 11 to
remove any remaining liquid.
Step 11 can be performed with any dryer commercially acceptable for
that purpose, for example, a spin dryer. After the granular masses
are dried they are transported for packaging and for shipment for
ultimate reclaiming.
Having set forth the description of their invention, Applicants now
turn to the claims directed to their invention. It being understood
that the claims appended hereto define the scope of Applicants'
invention.
* * * * *